VS hot migration fails with "error: internal error: Failed to reserve port" after restarting libvirtd

Issue

After you restart libvirtd, the VS hot migration fails with the "error: internal error: Failed to reserve port" error message.

Environment

Libvirt-4.5.0 and earlier versions

Resolution 

One of the possible solutions is to update the libvirt version and dependent packages to 4.6.0 or 5.0.0.

Versions of libvirt package and its dependencies were not tested by our QAs. Neither tested in general CentOS repo file. Perform at your own risk.

 Update may be performed the following way: 

1. Create repo file /etc/yum.repos.d/libvirt-latest.repo with following content:

   [centos-libvirt-latest]
   gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-SIG-Virtualization
   gpgcheck=1
   name=CentOS-$releasever - libvirt-latest
   baseurl=http://mirror.centos.org/centos-7/$releasever/virt/$basearch/libvirt-latest/
   enabled=1

     2. Clean yum cache and update libvirt:

# yum clean all
# yum update libvirt

    3. Restart libvirt:

# systemctl restart libvirtd

From now on, the VSs started after libvirtd upgrade will be successfully migrated from compute resources with upgraded libvirtd. For compute resources with older libvirtd packages, the issue will persist.

Cause

A bug in Libvirt-4.5.0 and earlier versions, which prevents the virtual servers' migration.